Radiator shop can check this while you wait in most cases.

 

Please call me crazy, but there's (2) tanks, (1) on each side, the coolant MUST flow through the tubing one side to the other.

luck,greg

 

Going to assume D2. First look under the coolant fill cap for a little streem of coolant with the engine running. What part of the thermostat did you bolck open? You must not remove or manualy open the part of the thermostat with the four little holes! (Looks like a large washer with four holes) If you did you completely bypass the radiator. Kinda sounds like what you got.